[tocomment]

Would t be possible to design something similar for a car wheel?

[willvarfar]

Regenerative braking http://en.wikipedia.org/wiki/Regenerative_brake is a mainstay of modern electric cars. They all do this.

[tocomment]

Yes but does the equivalent of a Copenhagen wheel exist for a car? That sir is my question.

[toomuchtodo]

You'd need a hub motor in each wheel, which causes the vehicle to have an excess of unsprung weight. So, not at the moment. If electric motors were to drastically come down in weight, possibly.

[seniorsassycat]

Do you mean an electric motor, battery, and regenerative system built into each of a cars wheels?

I think that a system like that would not be practical when scaled up to the size and energy demands of cars.

[dredmorbius]

For automobiles, incorporating the energy storage into the wheel itself would be a poor allocation of weight (and size). So most solutions revolve around (pardon the pun) batteries or flywheels housed within the chassis.

[mcgroob]

Like this? http://mtsunews.com/wheel-hub-retrofit-update/